The present invention relates to spouts that have internal back flow protection.
Plumbing codes typically require back flow protection when a plumbing outlet is likely to be adjacent contaminated water. For example, kitchen spray units of the type which can be pulled out from the sink or a faucet are typically provided with back flow protection. See e.g. U.S. Pat. No. 4,696,322. The disclosure of this patent and of all other publications referred to herein are incorporated by reference as if fully set forth herein.
Back flow protection has also been provided in stop cocks. See U.S. Pat. No. 2,133,804.
Back flow protection can be provided to some extent by including a one-way check valve in the supply line, or preferably (and/or additionally) by providing a means to bleed air into the fitting should upstream negative pressure develop (e.g. a supply line to a high rise apartment breaks). This latter approach significantly offsets any suction which might cause contaminated water to be sucked back into the line, and is known as vacuum breaking.
However, there is another type of faucet where the hot water is controlled by a first stop cock positioned at one location on a sink, the cold water is controlled by a second stop cock positioned at a second separate location on a sink, and outlets from both valves feed to a centrally located spout which has no valving to control water flow. While each such stop cock could be provided with separate vacuum breaker protection (compare U.S. Pat. No. 2,133,804), this requires two separate stop cocks to be modified to provide such protection.
Providing vacuum breaker protection in connection with such spouts is not typical as such spouts are often slanted upward so that their outlets are sufficiently far away from contaminated water below that plumbing codes don't usually require such protection. However, very low profile designs have been developed for such spouts where the outlet is very close to the base of the spout. Some plumbing codes require back flow protection in connection with such spouts.
Complicating matters is the fact that such designs are often provided with a pull up knob that rests on top of the spout. The knob is connected to an extension which projects downwardly through the spout in parallel to the water supply line to link to the drain control mechanism.
Thus, it can be seen that a need exists for back flow protection in such spouts.